1. Field of the Invention
This invention is directed to an apparatus for treating an airway condition of a patient. More particularly, this invention is directed to an apparatus and related kit of a cartridge for connection to a handle for delivering an implant into tissue of a patient's airway.
2. Description of the Prior Art
Airway conditions such as snoring and obstructive sleep apnea (OSA) have received increased scientific and academic attention. One publication estimates that up to 20% of the adult population snores habitually. Huang, et al., “Biomechanics of Snoring”, Endeavour, p. 96–100, Vol. 19, No. 3 (1995). Snoring can be a serious cause of marital discord. In addition, snoring can present a serious health risk to the snorer. In 10% of habitual snorers, collapse of the airway during sleep can lead to obstructive sleep apnea syndrome. Id.
Notwithstanding numerous efforts to address snoring and sleep apnea, effective treatments have been elusive. Such treatment may include mouth guards or other appliances worn by the snorer during sleep. However, patients find such appliances uncomfortable and frequently discontinue use (presumably adding to marital stress).
Electrical stimulation of the soft palate has been suggested to treat snoring and obstructive sleep apnea. See, e.g., Schwartz, et al., “Effects of electrical stimulation to the soft palate on snoring and obstructive sleep apnea”, J. Prosthetic Dentistry, pp. 273–281 (1996). Devices to apply such stimulation are described in U.S. Pat. Nos. 5,284,161 and 5,792,067. Such devices are appliances requiring patient adherence to a regimen of use as well as subjecting the patient to discomfort during sleep. Electrical stimulation to treat sleep apnea is discussed in Wiltfang, et al., “First results on daytime submandibular electrostimulation of suprahyoidal muscles to prevent night-time hypopharyngeal collapse in obstructive sleep apnea syndrome”, International Journal of Oral & Maxillofacial Surgery, pp. 21–25 (1999).
Surgical treatments have been employed. One such treatment is uvulopalatopharyngoplasty. In this procedure, so-called laser ablation is used to remove about 2 cm of the trailing edge of the soft palate thereby reducing the soft palate's ability to flutter between the tongue and the pharyngeal wall of the throat. The procedure is frequently effective to abate snoring but is painful and frequently results in undesirable side effects. Namely, removal of the soft palate trailing edge comprises the soft palate's ability to seal off nasal passages during swallowing and speech. In an estimated 25% of uvulopalatopharyngoplasty patients, fluid escapes from the mouth into the nose while drinking. Huang, et al., supra at 99. Uvulopalatopharyngoplasty (UPPP) is also described in Harries, et al., “The Surgical treatment of snoring”, Journal of Laryngology and Otology, pp. 1105–1106 (1996) which describes removal of up to 1.5 cm of the soft palate. Assessment of snoring treatment is discussed in Cole, et al., “Snoring: A review and a Reassessment”, Journal of Otolaryngology, pp. 303–306 (1995).
Novel treatments for snoring and sleep apnea are described in various patents commonly assigned with the present application. These include U.S. Pat. No. 6,250,307 to Conrad et al. dated Jun. 26, 2001 which describes (along with other embodiments) elongated implants for placement in the soft palate. In one embodiment, three such implants are placed in the soft palate. U.S. Pat. No. 6,578,580 to Conrad et al. dated Jun. 17, 2003 describes a needle (which may have a perforated distal tip) for delivery of an implant. The implant may be preloaded into the needle. In U.S. Pat. No. 6,523,542 to Metzger et al. dated Feb. 25, 2003, an implant is described as a sheet of felt or similar material delivered through a needle. U.S. Pat. No. 6,513,530 to Knudson et al. dated Feb. 4, 2003 describes the implant as a braid with welded ends near frayed ends. U.S. Pat. No. 6,431,174 to Knudson et al. dated Aug. 13, 2002 describes use of microbeads as implants as well as describing placement of implants in a pharyngeal wall or nasal area as well as a soft palate.
When placing implants in the tissue of a patient's airway (i.e., in soft palate, nasal or pharyngeal wall tissue), it may often be desirable to place more than one such implant (e.g., the three parallel longitudinal implants shown in the soft palate in the aforementioned U.S. Pat. No. 6,250,307). Delivery systems for such implants should accommodate the need for multiple implants, the need to protect the implant and delivery system from damage, facilitate ease and accuracy of implant placement and to maintain sterility. Also, such systems should be cost effective and minimize waste. It is an object of the present invention to provide such a delivery system.